An authentication system for digital records has a hash tree structure that computes an uppermost, root hash value that may be digitally signed. The housing provides strength and resistance to stress fracturing without the use of heavy materials, such as cast iron, or the use of ribs and recesses which can harbor contaminates. In case of upward movement of said elevator cabin hydraulic oil is conveyed by means of a pump driven by an electromotor, from said tank through said control valve unit to said lifting cylinder, whereas in case of downward movement of said elevator cabin said hydraulic oil flows through said control valve unit to the tank without the pump working. An ONOFF device in communication with the timer, the energy source and the heat generating component, is configured to disconnect the energy source from the heat generating component after the alarm time expires.